Dissertation Research: Behavioral Style and its Endocrine Correlates in Young Chimpanzees (Pan troglodytes)

Yale University, New Haven CT

Investigators

Abstract

Many psychologists have studied the influential role of personality in mediating how humans approach life. Physical anthropologists and primatologists have largely ignored this variable in nonhuman primates, focusing instead on the significance of a group-living individual's dominance rank in the social hierarchy. But using dominance rank to predict variables such as stress levels often proves unsatisfactory: dominance has been found to only weakly correlate with variables such as baseline hormone levels. In this project the researcher will consider the role of personality or behavioral style as an additional variable that explains differences between nonhuman primate individuals. Specifically, behavioral and physiological data from captive, peer-housed groups of young chimpanzees at the University of Southwest Louisiana Research Center in New Iberia, Louisiana will be collected. Individuals of similar rank with respect to variables that define behavioral styles will then be compared. For example, how good is individual X at picking fights that he/she can win? How adept is individual Y at forming valuable friendships? It is expected that these variables may not perfectly correlate with rank; a low-ranking individual may actually be quite good at picking winnable fights, for example. Individuals with different behavioral styles will be compared for urinary and serum hormone levels in order to assess the relative effects of dominance rank and behavioral style on stress physiology, health, and growth. It is predicted that consideration of behavioral style will provide for a fuller understanding of the factors affecting intra-group relations and physiological parameters than dominance rank alone, and will broaden our approach to primate socioecology.